AIM: The goal of this study was to characterize the AFP receptor, its possible signal transduction pathway and its proliferative functions in human hepatoma cell line Bel 7402. METHODS: Cell proliferation enhanced by ...AIM: The goal of this study was to characterize the AFP receptor, its possible signal transduction pathway and its proliferative functions in human hepatoma cell line Bel 7402. METHODS: Cell proliferation enhanced by AFP was detected by MTT assay, 3H-thymidine incorporation and S-stage percentage of cell cycle analysis. With radioactive labeled 125I-AFP for receptor binding assay; cAMP accumulation, protein kinase A activity were detected by radioactive immunosorbent assay and the change of intracellular free calcium (Ca2+i) was monitored by scanning fluorescence intensity under TCS-NT confocal microscope. The expression of oncogenes N- ras, p 53, and p21( ras ) in the cultured cells in vitro were detected by Northern blotting and Western blotting respectively. RESULTS: It was demonstrated that AFP enhanced the proliferation of human hepatoma Bel 7402 cell in a dose dependent fashion as shown in MTT assay, (3)H-thymidine incorporation and S-phase percentage up to 2-fold. Two subtypes of AFP receptors were identified in the cells with Kds of 1.3 x 10(-9)mol.L(-1) and 9.9 x10(-8)mol. (-1)L respectively. Pretreatment of cells with AFP resulted in a significant increase (625%) in cAMP accumulation. The activity of protein kinase A activity were increased up to 37.5, 122.6, 73.7 and 61.2% at treatment time point 2, 6, 12 and 24 hours. The level of intracellular calcium were elevated after the treatment of alpha-fetoprotein and achieved to 204% at 4 min. The results also showed that AFP(20mg.L(-1)) could upregulate the expression of N- ras oncogenes and p 53 and p21( ras ) in Bel 7402 cells. In the later case,the alteration were 81.1%(12h) and 97.3%(12h) respectively compared with control. CONCLUSION: These results demonstrate that AFP is a potential growth factor to promote the proliferation of human hepatoma Bel 7402 cells. Its growth-regulatory effects are mediated by its specific plasma membrane receptors coupled with its transmembrane signaling transduction through the pathway of cAMP-PKA and intracellular calcium to regulate the expression of oncogenes.展开更多
Hypoxia-inducible factor-1 (HIF-1), composed of HIF-α andHIF-13 subunits, is a heteroclimeric transcriptional activator.In response to hypoxia, stimulation of growth factors, andactivation of oncogenes as well as car...Hypoxia-inducible factor-1 (HIF-1), composed of HIF-α andHIF-13 subunits, is a heteroclimeric transcriptional activator.In response to hypoxia, stimulation of growth factors, andactivation of oncogenes as well as carcinogens, HIF-1α is overexpressed and/or activated and targets those geneswhich are required for angiogenesis, metabolic adaptationto low oxygen and promotes survival. HIF-1 is critical forboth physiological and pathological processes. Several dozensof putative direct HIF-1 target genes have been identifiedon the basis of one or more c/s-acting hypoxia-responseelements that contain an HIF-1 binding site. A variety ofregulators including growth factors, genetic alterations, stressactivators, and some carcinogens have been documentedfor regulation of HIF-1 in which several signaling pathwaysare involved depending on the stimuli and cell types.Activation of HIF-1 in combination with activated signalingpathways and regulators is implicated in tumour progressionand prognosis. This review presents a summary of thestructure and function of HIF-1α, and correlation amongspecific regulators and their signaling pathways.展开更多
AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to ...AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to cultured human hepatocellular carcinoma Bel 7402 cells in vitro for various treatment periods. The expression of c-fos, c-jun,and N-ras mRNA involved in proliferation and differentiation of cells was analyzed by Northern blot,and the expression of mutative p53 and p21^ras proteins was determined by Western blot.RESULTS:The results showed that AFP (20mg/L) stimulated mRNA expression of these oncogenes in Bel 7402 cells.The expression of c-fos mRNA increased by 51.1%,60.9%,96.0%,and 25.5% at 2, 6, 12, and 24 h, respectively.The expression of c-jun and N-ras mRNA reached to the maximum which increased by 81.3% and 59.9% as compared with the control alter 6h and 24h incubation with AFP, respectively.Western blot assay also demonstrated that AFP promoted the expression of mutative p53 and p21^ras proteins, and the increased rate of those proteins was 13.0%,39.9%, and 70.9%, as well as 35.2%, 102.6%, and 46.8% at 6, 12, and 24h,respectively, as compared with the control.Both human serum albumin (the same dosage as AFP) and monoclonal anti-AFP antibody failed to stimulate the expression of these oncogenes,but anti-AFP antibody could block the functions of AFP.CONCLUSION:The data indicate that AFP can stimulate the expression of some oncogenes to enhance the proliferation of human hepatocellular carcinoma Bel 7402 cells.展开更多
AIM: To analyze the risk factors for pancreatic leakage after pancreaticoduodenectomy (PD) and to evaluate whether duct-to-mucosa pancreaticojejunostomy could reduce the risk of pancreatic leakage. METHODS: Sixty-two ...AIM: To analyze the risk factors for pancreatic leakage after pancreaticoduodenectomy (PD) and to evaluate whether duct-to-mucosa pancreaticojejunostomy could reduce the risk of pancreatic leakage. METHODS: Sixty-two patients who underwent PD at our hospital between January 2000 and November 2003 were reviewed retrospectively. The primary diseases of the patients included pancreas cancer, ampullary cancer, bile duct cancer, islet cell cancer, duodenal cancer, chronic pancreatitis, pancreatic cystadenoma, and gastric cancer. Standard PD was performed for 25 cases, PD with extended lymphadenectomy for 27 cases, pylorus-preserving PD for 10 cases. A duct-to-mucosa pancreaticojejunostomy was performed for patients with a hard pancreas and a dilated pancreatic duct, and a traditional end-to-end invagination pancreaticojejunostomy for patients with a soft pancreas and a non-dilated duct. Patients were divided into two groups according to the incidence of postoperative pancreaticojejunal anastomotic leakage: 10 cases with leakage and 52 cases without leakage. Seven preoperative and six intraoperative risk factors with the potential to affect the incidence of pancreatic leakage were analyzed with SPSS10.0 software. Logistic regression was then used to determine the effect of multiple factors on pancreatic leakage. RESULTS: Of the 62 patients, 10 (16.13%) were identified as having pancreatic leakage after operation. Other major postoperative complications included delayed gastric emptying (eight patients), abdominal bleeding (four patients), abdominal abscess (three patients) and wound infection (two patients). The overall surgical morbidity was 43.5% (27/62). The hospital mortality in this series was 4.84% (3/62), and the mortality associated with pancreatic fistula was 10% (1/10). Sixteen cases underwent duct-to-mucosa pancreaticojejunostomy and 1 case (1/16, 6.25%) devel-oped postoperative pancreatic leakage, 46 cases underwent invagination pancreaticojejunostomy and 9 cases (9/46, 19.6%) developed postoperative pancreatic leakage. General risk factors including patient age, gender, history of jaundice, preoperative nutrition, pathological diagnosis and the length of postoperative stay were similar in the two groups. There was no statistical difference in the incidence of pancreatic leakage between the patients who received the prophylactic use of octreotide after surgery and the patients who did not undergo somatostatin therapy. Moreover, multivariate logistic regression analysis showed that none of the above factors seemed to be associated with pancreatic fistula. Two intraoperative risk factors, pancreatic duct size and texture of the remnant pancreas, were found to be significantly associated with pancreatic leakage. The incidence of pancreatic leakage was 4.88% in patients with a pancreatic duct size greater than or equal to 3 mm and was 38.1% in those with ducts smaller than 3 mm (P = 0.002). The pancreatic leakage rate was 2.94% in patients with a hard pancreas and was 32.1% in those with a soft pancreas (P = 0.004). Operative time, blood loss and type of resection were similar in the two patient groups. The incidence of pancreatic leakage was 6.25% (1/16) in patients with duct-to-mucosa anastomosis, and was 19.6% (9/46) in those with traditional invagination anastomosis. Although the difference of pancreatic leakage between the two groups was obvious, no statistical signific-ance was found. This may be due to the small number of patients with duct-to-mucosa anastomosis. By further analyzing with multivariate logistic regression, both pancreatic duct size and texture of the remnant pancreas were demonstrated to be independent risk factors (P= 0.007 and 0.017, OR = 11.87 and 15.45). Although anastomotic technique was not a significant factor, pancreatic leakage rate was much less in cases that underwent duct-to-mucosa pancreaticojejunostomy. CONCLUSION: Pancreatic duct size and texture of the remnant pancreas are risk factors influencing pancreatic leakage after PD. Duct-to-mucosa pancreaticojejunostomy, as a safe and useful anastomotic technique, can reduce pancreatic leakage rate after PD.展开更多
AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polype...AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polypeptidefragment of antigen determinate with 12 amino acidsresidues was synthesized. Monoclonal antibody against thispeptide fragment was prepared. Proliferation of Mouse NS-L cells treated with methionine enkephalin of 1x10-6 mol.L-1was observed. The activities of protein kinase A (PKA) andprotein kinase C (PKC) were measured and thereby themechanism of effect of methionine enkephalin was postulated.RESULTS: The results demonstrated that methionineenkephalin could enhance the proliferation of NS-1 cells andthe effect of methionine enkephalin could be particularlyblocked by monoclonal antibody. The activity of PKA wasincreased in both cytosol and cell membrane. With referenceto PKC, the intracellular activity of PKC in NS-1 cells waselevated at 1x10-7 mol.L-1 and then declined gradually asthe concentration of methionine enkephalin was raised. Theeffects of methionine enkephalin might be reversed by bothnaloxone and monoclonal antibody.CONCLUSION: Coupled with the findings, it in-dicates thatthe signal transduction systems via PKA and PKC are involvedin the effects of methionine enkephalin by binding with thetraditional opioid receptors, and therefore resulting in differentbiological effects.展开更多
AIM: Inducible nitric oxide synthase (iNOS) plays a central role in the pathway of reactive oxygen and nitrogen species metabolism when Helicobacter pylori (H pylon) infection occurs in humans, iNOS Ser^608 Leu allele...AIM: Inducible nitric oxide synthase (iNOS) plays a central role in the pathway of reactive oxygen and nitrogen species metabolism when Helicobacter pylori (H pylon) infection occurs in humans, iNOS Ser^608 Leu allele, a novel genetic polymorphism (C/T) occurring within exon 16 of the iNOS reductase domain, may have a dramatic effect on the enzymatic activity. The aim of this study was to determine whether iNOS C/T polymorphism was associated with increased susceptibility to gastric cancer. METHODS: We conducted a population based case-control study in a high gastric cancer incidence area, Yangzhong, China. Questionnaires from 93 patients with intestinal type gastric cancer (IGC), 50 with gastric cardia cancer (GCC) and 246 healthy controls were obtained between 1997 and 1998, and iNOS genotyping was carried out. Odds ratios (ORs), interaction index (γ), and 95% confidence intervals for the combined effects of iNOS genotype and H pylori infection, cigarette smoking or alcohol drinking were estimated. RESULTS: The frequency of (CT+TT) genotypes was higher in cases than in control group (24.48% vs 23.17%), but the difference was not statistically significant. After adjusting for age and gender, past cigarette smokers with (CT+TT) genotypes had a significantly increased risk of IGC (OR=3.62, 95% CI:1.23-10.64), while past alcohol drinkers with (CT+TT) genotypes had a significantly increased risk of GCC (OR=3.33, 95% CI:1.14-9.67). H pylori CagA negative subjects with (CT+TT) genotypes had a significantly increased risk of both IGC and GCC (OR=2.19 and 3.52, respectively). CONCLUSION: iNOS Ser^608 Leu allele may be a potential determinant of susceptibility to cigarette -alcohol induced gastric cancer, but larger studies are needed to confirm the observations.展开更多
AIM:Taurine has been shown to be an effective scavenger of hypochlorous acid (HOCI).The role of HOCI is well established in tissue damage associated with inflammation and injury. In the present study, the effect of HO...AIM:Taurine has been shown to be an effective scavenger of hypochlorous acid (HOCI).The role of HOCI is well established in tissue damage associated with inflammation and injury. In the present study, the effect of HOCl on nuclear nucleoside triphosphatase of hepatocytes and the ability of taurine to prevent this effect were investigated.METHODS:Isolated hepatic nuclei from rat liver were exposed to HOCl with or without taurine. The NTPase activity on nuclear envelope was assayed using ATP and GTP as substrates, respectively.RESULTS:The first series of experiments evaluated the toxicity of HOCl and the efficacy of taurine to protect NTPase.HOCI at 10^-9-5×10^-6 mol/L reduced nuclear NTPase activities in a concentration dependent manner (ATP and GTP as substrates) (P<0.01). HOCl at 10^-6mol/L reduced the NTPase activity by 65% (ATP as substrate) and 76% (GTP assubstrate). Taurine (10^-7 to 10^-4mol/L) was tested forprotection against HOCl at 10^-6mol/L and the nuclei treated with 5×10^-4mol/L taurine exhibited only 20% and 12% reduction in NTPase activities compared to untreated controls. A second study was performed comparing taurine to glutathione (GSH). GSH and HOCl at 10^-6mol/L exhibited 46% and 67.4% reduction in NTPase activities compared with control. GSH (10^-4mol/L) which was incubated with the nuclei and HOCI still exhibited 44.2% and 44.8% reduction in NTPase activities of untreated control. Taurine with HOCl only exhibited 15.2% and 17.1% reduction in NTPase activities, which provided more powerful protection against HOCI than GSH. The third experiment was undertaken to evaluate the specificity of taurine against HOCl. Incubation of rat hepatic nuclei with Fe^3+/H2O2 (1mmol/L vs 5μmol/L) resulted in a decrease in nuclear NTPase activities (P<0.01).When hepatic nuclei were incubated with Tau (10^-4mol/L) and Fe^3+/H2O2 (1mmol/L vs 5μmol/L), nuclear NTPase activities were only slightly increased as compared with that of incubation with Fe^3+/H2O2 alone. However, GSH failed to alter the NTPase activities induced by Fe^3+/H2O2.CONCLUSION:The present findings indicate that HOCl can act as an inhibitor of nuclear NTPase. Taurine can antagonistically reduce the toxicity of HOCI to NTPase.展开更多
AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotype...AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes.METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Hah ethical origin, to perform this casecontrol study. The haplotypes with significant difference in the gene (s) were further analyzed.RFSULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP,rs436045 in the protein kinase C/ζgene (PRKCZ) was statistically different between the case and control groups (P＜0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified.CONCLUSION: PRKCZgene may be associated with type 2 diabetes in Hah population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.展开更多
The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that ...The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that GST-sHLA-G1α chain could bind to its receptor ILT-2 on NK92 cells and then the latter recruited Src homology 2 domaincontaining tyrosine phosphatase-1 (SHP-1), which consequently dephosphorylated some important protein tyrosine kinases and blocked the activation of downstream molecules such as MEK and ERK so that the cytotoxicity of natural killer (NK) cells was inhibited. These results indicated that GST-sHLA-G1α chain might be exploited in new immunotherapy strategies aiming at inducing immunotolerance during allograft, xenograft and autoimmune situations. In addition, we found that modification of O-linked β-N-acetylglucosamine (O-GlcNAc) was involved in NK cells' activating and inhibitory signals. This may provide a novel molecular target for inducing immunotolerance but needs further study.展开更多
AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) an...AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene.RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT.CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.展开更多
AIM: To identify the expression of Caspase-l(interleukin1.β converting enzyme) and its role in adenoma of the pancreas and chronic pancreatitis.METHODS: The expression of Caspase-1 was assessed in 42 pancreatic cance...AIM: To identify the expression of Caspase-l(interleukin1.β converting enzyme) and its role in adenoma of the pancreas and chronic pancreatitis.METHODS: The expression of Caspase-1 was assessed in 42 pancreatic cancer tissue samples, 38 chronic pancreatitis specimens, and 9 normal pancreatic tissues by immunohistochemistry and Western blot analysis.RESULTS: Overexpression of Caspase-1 was observed in both disorders, but there were differences in the expression patterns in distinct morphologic compartments. Pancreatic cancer tissues showed a clear cytoplasmatic overexpression of Caspase-1 in tumor cells of 71% of the tumors, whereas normal pancreatic tissues showed only occasional immunoreactivity. In chronic pancreatitis, overexpression of Caspase-1 was found in atrophic acinar cells (89 %),hyperplastic ducts (87 %), and dedifferentiating acinar cells (84 %). Although in atrophic cells a clear nuclear expression was found, hyperplastic ducts and dedifferentiating acinar cells showed dear cytoplasmic expression. Western blot analysis revealed a marked expression of the 45 kDa precursor of Caspase-1 in pancreatic cancer and chronic pancreatitis (80 %and 86 %, respectively). Clear bands at 30 kDa, which suggested the p10-p20 heterodimer of active Caspase-1, were found in 60 % of the cancer tissue and 14 % of the pancreatitis tissue specimens, but not in normal pancreatic tissues.CONCLUSION: Overexpression of Caspase-1 is a frequent event in pancreatic disorders and its differential expression patterns may reflect two functions of the protease. One is its participation in the apoptotic pathway in atrophic acinar cells and tumor-surrounding pancreatitis tissue, the other is its possible role in proliferative processes in pancreatic cancer cells and hyperplastic duct cells and dedifferentiating acinar cells in chronic pancreatitis.展开更多
Immunization with inactivated autoreactive T cells(T cell vaccination) selected from individual's own T cell repertoire provides a unique in vivo setting for testing immune regulation that is known to involve inte...Immunization with inactivated autoreactive T cells(T cell vaccination) selected from individual's own T cell repertoire provides a unique in vivo setting for testing immune regulation that is known to involve interactions of a variety of related surface molecules(1).It induces regulatory immune responses that closely resemble the in vivo situation where the immune system is challenged by clonal activation and expansion of given T cell populations in various autoimmune diseases.T cell vaccination provides a powerful means of eliciting natural reactions of the immune system in response to clonal expansion of T cells,which can be used as a therapeutic approach to suppress or eliminate specific pathogenic autoreactive T cells in autoimmune conditions.Clinical trials using T cell vaccination to deplete autoreactive T cells in human autoimmune conditions have begun to reveal the pathologic relevance of various autoimmune T cell populations in the disease processes,providing a unique opportunity to test the autoimmune theories in a clinical setting.Cellular & Molecular Immunology. 2004;1(5):321-327.展开更多
Background Recently, arsenic trioxide (As 2O 3) was considered as a novel anti tumor agent However, it showed severe toxicity effect on normal tissue at the same time To improve its therapeutic efficacy and de...Background Recently, arsenic trioxide (As 2O 3) was considered as a novel anti tumor agent However, it showed severe toxicity effect on normal tissue at the same time To improve its therapeutic efficacy and decrease its toxicity,we prepared arsenic trioxide loaded albuminutes immuno nanospheres [As 2O 3 (HAS NS) BDI 1] targeted with nonoclonal antibody (McAb) BDI 1 and tested its specific killing effect against bladder cancer cell Methods As 2O 3 HAS NS was prepared by chemical cross linking method Monoclonal antibody BDI 1 was purified with ammonium sulphate saltingout and chromatography Albuminutes microspheres were conjugated with McAb by SPDP cross linking method Concentration of As in As 2O 3 (HAS NS) BDI 1 and As 2O 3 HAS NS was measured by atomic fluometry method As 2O 3 (HAS NS) BDI 1 and its activity were detected by SDS PAGE reduction electrophoresis, indirect immunofluorescence test, light microscope and scanning electron microscope observation Acridine orange staining and tritiated thymidine ( 3H TdR) incorporation tests were used to indicate specific killing activity of As 2O 3 (HAS NS) BDI 1 in vitro Results In As 2O 3 (HAS NS) BDI 1 groups, we saw two protein bands in SDS PAGE reduction electrophoresis Albuminutes immuno nanospheres were rounded with clear green fluorescence by immunofluorescence test Under microscope, we observed that BIU 87 cells were covered with the As 2O 3 (HAS NS) BDI 1 and that As 2O 3 (HAS NS) BDI 1 moved with the BIU 87 cells The albuminutes immuno nanospheres were tightly junctioned with the BIU 87 cells Specific killing activity of As 2O 3 (HAS NS) BDI 1 on bladder tumor cells was observed by acridine orange staining and 3H TdR incorporation assays Conclusions As 2O 3 (HAS NS) BDI 1 might bind specifically against BIU 87 cells, thus leading to high activity of killing bladder tumor cells展开更多
基金National Natural Science Foundation of China,No.39760077
文摘AIM: The goal of this study was to characterize the AFP receptor, its possible signal transduction pathway and its proliferative functions in human hepatoma cell line Bel 7402. METHODS: Cell proliferation enhanced by AFP was detected by MTT assay, 3H-thymidine incorporation and S-stage percentage of cell cycle analysis. With radioactive labeled 125I-AFP for receptor binding assay; cAMP accumulation, protein kinase A activity were detected by radioactive immunosorbent assay and the change of intracellular free calcium (Ca2+i) was monitored by scanning fluorescence intensity under TCS-NT confocal microscope. The expression of oncogenes N- ras, p 53, and p21( ras ) in the cultured cells in vitro were detected by Northern blotting and Western blotting respectively. RESULTS: It was demonstrated that AFP enhanced the proliferation of human hepatoma Bel 7402 cell in a dose dependent fashion as shown in MTT assay, (3)H-thymidine incorporation and S-phase percentage up to 2-fold. Two subtypes of AFP receptors were identified in the cells with Kds of 1.3 x 10(-9)mol.L(-1) and 9.9 x10(-8)mol. (-1)L respectively. Pretreatment of cells with AFP resulted in a significant increase (625%) in cAMP accumulation. The activity of protein kinase A activity were increased up to 37.5, 122.6, 73.7 and 61.2% at treatment time point 2, 6, 12 and 24 hours. The level of intracellular calcium were elevated after the treatment of alpha-fetoprotein and achieved to 204% at 4 min. The results also showed that AFP(20mg.L(-1)) could upregulate the expression of N- ras oncogenes and p 53 and p21( ras ) in Bel 7402 cells. In the later case,the alteration were 81.1%(12h) and 97.3%(12h) respectively compared with control. CONCLUSION: These results demonstrate that AFP is a potential growth factor to promote the proliferation of human hepatoma Bel 7402 cells. Its growth-regulatory effects are mediated by its specific plasma membrane receptors coupled with its transmembrane signaling transduction through the pathway of cAMP-PKA and intracellular calcium to regulate the expression of oncogenes.
基金Supported by Key Project of Science and Technology from Committee of Beijing Science and Technology (H020920030390)
文摘Hypoxia-inducible factor-1 (HIF-1), composed of HIF-α andHIF-13 subunits, is a heteroclimeric transcriptional activator.In response to hypoxia, stimulation of growth factors, andactivation of oncogenes as well as carcinogens, HIF-1α is overexpressed and/or activated and targets those geneswhich are required for angiogenesis, metabolic adaptationto low oxygen and promotes survival. HIF-1 is critical forboth physiological and pathological processes. Several dozensof putative direct HIF-1 target genes have been identifiedon the basis of one or more c/s-acting hypoxia-responseelements that contain an HIF-1 binding site. A variety ofregulators including growth factors, genetic alterations, stressactivators, and some carcinogens have been documentedfor regulation of HIF-1 in which several signaling pathwaysare involved depending on the stimuli and cell types.Activation of HIF-1 in combination with activated signalingpathways and regulators is implicated in tumour progressionand prognosis. This review presents a summary of thestructure and function of HIF-1α, and correlation amongspecific regulators and their signaling pathways.
基金Supported by the National Natural Science Foundation of China,No.30260117Natural Science Foundation of Hainan Province,No.30315 the Nursery Foundation of Hainan Medical College,No.200202
文摘AIM:To investigate the molecular mechanism of alphafetoprotein (AFP) on regulating the proliferation of human hepatocellular carcinoma cells.METHODS: Alpha-fetoprotein purified from human umbilical blood was added to cultured human hepatocellular carcinoma Bel 7402 cells in vitro for various treatment periods. The expression of c-fos, c-jun,and N-ras mRNA involved in proliferation and differentiation of cells was analyzed by Northern blot,and the expression of mutative p53 and p21^ras proteins was determined by Western blot.RESULTS:The results showed that AFP (20mg/L) stimulated mRNA expression of these oncogenes in Bel 7402 cells.The expression of c-fos mRNA increased by 51.1%,60.9%,96.0%,and 25.5% at 2, 6, 12, and 24 h, respectively.The expression of c-jun and N-ras mRNA reached to the maximum which increased by 81.3% and 59.9% as compared with the control alter 6h and 24h incubation with AFP, respectively.Western blot assay also demonstrated that AFP promoted the expression of mutative p53 and p21^ras proteins, and the increased rate of those proteins was 13.0%,39.9%, and 70.9%, as well as 35.2%, 102.6%, and 46.8% at 6, 12, and 24h,respectively, as compared with the control.Both human serum albumin (the same dosage as AFP) and monoclonal anti-AFP antibody failed to stimulate the expression of these oncogenes,but anti-AFP antibody could block the functions of AFP.CONCLUSION:The data indicate that AFP can stimulate the expression of some oncogenes to enhance the proliferation of human hepatocellular carcinoma Bel 7402 cells.
文摘AIM: To analyze the risk factors for pancreatic leakage after pancreaticoduodenectomy (PD) and to evaluate whether duct-to-mucosa pancreaticojejunostomy could reduce the risk of pancreatic leakage. METHODS: Sixty-two patients who underwent PD at our hospital between January 2000 and November 2003 were reviewed retrospectively. The primary diseases of the patients included pancreas cancer, ampullary cancer, bile duct cancer, islet cell cancer, duodenal cancer, chronic pancreatitis, pancreatic cystadenoma, and gastric cancer. Standard PD was performed for 25 cases, PD with extended lymphadenectomy for 27 cases, pylorus-preserving PD for 10 cases. A duct-to-mucosa pancreaticojejunostomy was performed for patients with a hard pancreas and a dilated pancreatic duct, and a traditional end-to-end invagination pancreaticojejunostomy for patients with a soft pancreas and a non-dilated duct. Patients were divided into two groups according to the incidence of postoperative pancreaticojejunal anastomotic leakage: 10 cases with leakage and 52 cases without leakage. Seven preoperative and six intraoperative risk factors with the potential to affect the incidence of pancreatic leakage were analyzed with SPSS10.0 software. Logistic regression was then used to determine the effect of multiple factors on pancreatic leakage. RESULTS: Of the 62 patients, 10 (16.13%) were identified as having pancreatic leakage after operation. Other major postoperative complications included delayed gastric emptying (eight patients), abdominal bleeding (four patients), abdominal abscess (three patients) and wound infection (two patients). The overall surgical morbidity was 43.5% (27/62). The hospital mortality in this series was 4.84% (3/62), and the mortality associated with pancreatic fistula was 10% (1/10). Sixteen cases underwent duct-to-mucosa pancreaticojejunostomy and 1 case (1/16, 6.25%) devel-oped postoperative pancreatic leakage, 46 cases underwent invagination pancreaticojejunostomy and 9 cases (9/46, 19.6%) developed postoperative pancreatic leakage. General risk factors including patient age, gender, history of jaundice, preoperative nutrition, pathological diagnosis and the length of postoperative stay were similar in the two groups. There was no statistical difference in the incidence of pancreatic leakage between the patients who received the prophylactic use of octreotide after surgery and the patients who did not undergo somatostatin therapy. Moreover, multivariate logistic regression analysis showed that none of the above factors seemed to be associated with pancreatic fistula. Two intraoperative risk factors, pancreatic duct size and texture of the remnant pancreas, were found to be significantly associated with pancreatic leakage. The incidence of pancreatic leakage was 4.88% in patients with a pancreatic duct size greater than or equal to 3 mm and was 38.1% in those with ducts smaller than 3 mm (P = 0.002). The pancreatic leakage rate was 2.94% in patients with a hard pancreas and was 32.1% in those with a soft pancreas (P = 0.004). Operative time, blood loss and type of resection were similar in the two patient groups. The incidence of pancreatic leakage was 6.25% (1/16) in patients with duct-to-mucosa anastomosis, and was 19.6% (9/46) in those with traditional invagination anastomosis. Although the difference of pancreatic leakage between the two groups was obvious, no statistical signific-ance was found. This may be due to the small number of patients with duct-to-mucosa anastomosis. By further analyzing with multivariate logistic regression, both pancreatic duct size and texture of the remnant pancreas were demonstrated to be independent risk factors (P= 0.007 and 0.017, OR = 11.87 and 15.45). Although anastomotic technique was not a significant factor, pancreatic leakage rate was much less in cases that underwent duct-to-mucosa pancreaticojejunostomy. CONCLUSION: Pancreatic duct size and texture of the remnant pancreas are risk factors influencing pancreatic leakage after PD. Duct-to-mucosa pancreaticojejunostomy, as a safe and useful anastomotic technique, can reduce pancreatic leakage rate after PD.
基金National Science Foundation of China,No.30060091
文摘AIM: To investigate experimentally the effects of methionineenkephalin on signal transduction of mouse myeloma NS-1cells.METHODS: The antigen determinate of delta opioidreceptor was designed in this lab and the polypeptidefragment of antigen determinate with 12 amino acidsresidues was synthesized. Monoclonal antibody against thispeptide fragment was prepared. Proliferation of Mouse NS-L cells treated with methionine enkephalin of 1x10-6 mol.L-1was observed. The activities of protein kinase A (PKA) andprotein kinase C (PKC) were measured and thereby themechanism of effect of methionine enkephalin was postulated.RESULTS: The results demonstrated that methionineenkephalin could enhance the proliferation of NS-1 cells andthe effect of methionine enkephalin could be particularlyblocked by monoclonal antibody. The activity of PKA wasincreased in both cytosol and cell membrane. With referenceto PKC, the intracellular activity of PKC in NS-1 cells waselevated at 1x10-7 mol.L-1 and then declined gradually asthe concentration of methionine enkephalin was raised. Theeffects of methionine enkephalin might be reversed by bothnaloxone and monoclonal antibody.CONCLUSION: Coupled with the findings, it in-dicates thatthe signal transduction systems via PKA and PKC are involvedin the effects of methionine enkephalin by binding with thetraditional opioid receptors, and therefore resulting in differentbiological effects.
基金Supported by Grants From the National Natural Science Foundation of China (30170827 to Jing.Shen and 30070671 to Run-Tian Wang)
文摘AIM: Inducible nitric oxide synthase (iNOS) plays a central role in the pathway of reactive oxygen and nitrogen species metabolism when Helicobacter pylori (H pylon) infection occurs in humans, iNOS Ser^608 Leu allele, a novel genetic polymorphism (C/T) occurring within exon 16 of the iNOS reductase domain, may have a dramatic effect on the enzymatic activity. The aim of this study was to determine whether iNOS C/T polymorphism was associated with increased susceptibility to gastric cancer. METHODS: We conducted a population based case-control study in a high gastric cancer incidence area, Yangzhong, China. Questionnaires from 93 patients with intestinal type gastric cancer (IGC), 50 with gastric cardia cancer (GCC) and 246 healthy controls were obtained between 1997 and 1998, and iNOS genotyping was carried out. Odds ratios (ORs), interaction index (γ), and 95% confidence intervals for the combined effects of iNOS genotype and H pylori infection, cigarette smoking or alcohol drinking were estimated. RESULTS: The frequency of (CT+TT) genotypes was higher in cases than in control group (24.48% vs 23.17%), but the difference was not statistically significant. After adjusting for age and gender, past cigarette smokers with (CT+TT) genotypes had a significantly increased risk of IGC (OR=3.62, 95% CI:1.23-10.64), while past alcohol drinkers with (CT+TT) genotypes had a significantly increased risk of GCC (OR=3.33, 95% CI:1.14-9.67). H pylori CagA negative subjects with (CT+TT) genotypes had a significantly increased risk of both IGC and GCC (OR=2.19 and 3.52, respectively). CONCLUSION: iNOS Ser^608 Leu allele may be a potential determinant of susceptibility to cigarette -alcohol induced gastric cancer, but larger studies are needed to confirm the observations.
基金Supported by the Major State Basic Research Development Program of People's Republic of China,No.G2000056905 and the National Natural Science Foundation of China,No.30070308
文摘AIM:Taurine has been shown to be an effective scavenger of hypochlorous acid (HOCI).The role of HOCI is well established in tissue damage associated with inflammation and injury. In the present study, the effect of HOCl on nuclear nucleoside triphosphatase of hepatocytes and the ability of taurine to prevent this effect were investigated.METHODS:Isolated hepatic nuclei from rat liver were exposed to HOCl with or without taurine. The NTPase activity on nuclear envelope was assayed using ATP and GTP as substrates, respectively.RESULTS:The first series of experiments evaluated the toxicity of HOCl and the efficacy of taurine to protect NTPase.HOCI at 10^-9-5×10^-6 mol/L reduced nuclear NTPase activities in a concentration dependent manner (ATP and GTP as substrates) (P<0.01). HOCl at 10^-6mol/L reduced the NTPase activity by 65% (ATP as substrate) and 76% (GTP assubstrate). Taurine (10^-7 to 10^-4mol/L) was tested forprotection against HOCl at 10^-6mol/L and the nuclei treated with 5×10^-4mol/L taurine exhibited only 20% and 12% reduction in NTPase activities compared to untreated controls. A second study was performed comparing taurine to glutathione (GSH). GSH and HOCl at 10^-6mol/L exhibited 46% and 67.4% reduction in NTPase activities compared with control. GSH (10^-4mol/L) which was incubated with the nuclei and HOCI still exhibited 44.2% and 44.8% reduction in NTPase activities of untreated control. Taurine with HOCl only exhibited 15.2% and 17.1% reduction in NTPase activities, which provided more powerful protection against HOCI than GSH. The third experiment was undertaken to evaluate the specificity of taurine against HOCl. Incubation of rat hepatic nuclei with Fe^3+/H2O2 (1mmol/L vs 5μmol/L) resulted in a decrease in nuclear NTPase activities (P<0.01).When hepatic nuclei were incubated with Tau (10^-4mol/L) and Fe^3+/H2O2 (1mmol/L vs 5μmol/L), nuclear NTPase activities were only slightly increased as compared with that of incubation with Fe^3+/H2O2 alone. However, GSH failed to alter the NTPase activities induced by Fe^3+/H2O2.CONCLUSION:The present findings indicate that HOCl can act as an inhibitor of nuclear NTPase. Taurine can antagonistically reduce the toxicity of HOCI to NTPase.
基金the National Natural Science Foundation of China, No.39896200,No30170441the National High Technology Research and Development Program,No.2001AA221161,No.2002BA711A05,No.2002BA71 IA10-02+1 种基金The National Program for Key Basic Research Projects,No.G1998051016the Natural Science Foundation of Beijing,No.7002026
文摘AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes.METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Hah ethical origin, to perform this casecontrol study. The haplotypes with significant difference in the gene (s) were further analyzed.RFSULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP,rs436045 in the protein kinase C/ζgene (PRKCZ) was statistically different between the case and control groups (P＜0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified.CONCLUSION: PRKCZgene may be associated with type 2 diabetes in Hah population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.
文摘The soluble HLA-G1 (sHLA-G1) isoform was found to be secreted by trophoblast cells at the matemo-fetal interface, which suggests that it may act as an immunomodulator during pregnancy. In this paper, we reported that GST-sHLA-G1α chain could bind to its receptor ILT-2 on NK92 cells and then the latter recruited Src homology 2 domaincontaining tyrosine phosphatase-1 (SHP-1), which consequently dephosphorylated some important protein tyrosine kinases and blocked the activation of downstream molecules such as MEK and ERK so that the cytotoxicity of natural killer (NK) cells was inhibited. These results indicated that GST-sHLA-G1α chain might be exploited in new immunotherapy strategies aiming at inducing immunotolerance during allograft, xenograft and autoimmune situations. In addition, we found that modification of O-linked β-N-acetylglucosamine (O-GlcNAc) was involved in NK cells' activating and inhibitory signals. This may provide a novel molecular target for inducing immunotolerance but needs further study.
基金Supported by the National Natural Science Foundation of China, No. 30170363 the Major Science and Technology Program of Ministry of Education, No. 01003 the Major State Basic Research Development Program of China, No. 2002CB513100 the National Key Technology Research and Development Program of China during the 10~(th) Five-Year Plan Period, No. 2001BA703B05
文摘AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene.RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT.CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.
文摘AIM: To identify the expression of Caspase-l(interleukin1.β converting enzyme) and its role in adenoma of the pancreas and chronic pancreatitis.METHODS: The expression of Caspase-1 was assessed in 42 pancreatic cancer tissue samples, 38 chronic pancreatitis specimens, and 9 normal pancreatic tissues by immunohistochemistry and Western blot analysis.RESULTS: Overexpression of Caspase-1 was observed in both disorders, but there were differences in the expression patterns in distinct morphologic compartments. Pancreatic cancer tissues showed a clear cytoplasmatic overexpression of Caspase-1 in tumor cells of 71% of the tumors, whereas normal pancreatic tissues showed only occasional immunoreactivity. In chronic pancreatitis, overexpression of Caspase-1 was found in atrophic acinar cells (89 %),hyperplastic ducts (87 %), and dedifferentiating acinar cells (84 %). Although in atrophic cells a clear nuclear expression was found, hyperplastic ducts and dedifferentiating acinar cells showed dear cytoplasmic expression. Western blot analysis revealed a marked expression of the 45 kDa precursor of Caspase-1 in pancreatic cancer and chronic pancreatitis (80 %and 86 %, respectively). Clear bands at 30 kDa, which suggested the p10-p20 heterodimer of active Caspase-1, were found in 60 % of the cancer tissue and 14 % of the pancreatitis tissue specimens, but not in normal pancreatic tissues.CONCLUSION: Overexpression of Caspase-1 is a frequent event in pancreatic disorders and its differential expression patterns may reflect two functions of the protease. One is its participation in the apoptotic pathway in atrophic acinar cells and tumor-surrounding pancreatitis tissue, the other is its possible role in proliferative processes in pancreatic cancer cells and hyperplastic duct cells and dedifferentiating acinar cells in chronic pancreatitis.
基金The work was supported by grants from Chinese Academy of Sciences(KSCX2-SW-212)Chinese Ministry of Science and Technology(863 Project 2002AA216121 and 202CCCD2000)Shanghai Commission of Science and Technology(01JC14036,200143 19207 and 03XD14015).
文摘Immunization with inactivated autoreactive T cells(T cell vaccination) selected from individual's own T cell repertoire provides a unique in vivo setting for testing immune regulation that is known to involve interactions of a variety of related surface molecules(1).It induces regulatory immune responses that closely resemble the in vivo situation where the immune system is challenged by clonal activation and expansion of given T cell populations in various autoimmune diseases.T cell vaccination provides a powerful means of eliciting natural reactions of the immune system in response to clonal expansion of T cells,which can be used as a therapeutic approach to suppress or eliminate specific pathogenic autoreactive T cells in autoimmune conditions.Clinical trials using T cell vaccination to deplete autoreactive T cells in human autoimmune conditions have begun to reveal the pathologic relevance of various autoimmune T cell populations in the disease processes,providing a unique opportunity to test the autoimmune theories in a clinical setting.Cellular & Molecular Immunology. 2004;1(5):321-327.
基金ThisstudywassupportedbyNationalYouthNatureScienceFoundationofChina (No 3 0 2 0 0 2 84)
文摘Background Recently, arsenic trioxide (As 2O 3) was considered as a novel anti tumor agent However, it showed severe toxicity effect on normal tissue at the same time To improve its therapeutic efficacy and decrease its toxicity,we prepared arsenic trioxide loaded albuminutes immuno nanospheres [As 2O 3 (HAS NS) BDI 1] targeted with nonoclonal antibody (McAb) BDI 1 and tested its specific killing effect against bladder cancer cell Methods As 2O 3 HAS NS was prepared by chemical cross linking method Monoclonal antibody BDI 1 was purified with ammonium sulphate saltingout and chromatography Albuminutes microspheres were conjugated with McAb by SPDP cross linking method Concentration of As in As 2O 3 (HAS NS) BDI 1 and As 2O 3 HAS NS was measured by atomic fluometry method As 2O 3 (HAS NS) BDI 1 and its activity were detected by SDS PAGE reduction electrophoresis, indirect immunofluorescence test, light microscope and scanning electron microscope observation Acridine orange staining and tritiated thymidine ( 3H TdR) incorporation tests were used to indicate specific killing activity of As 2O 3 (HAS NS) BDI 1 in vitro Results In As 2O 3 (HAS NS) BDI 1 groups, we saw two protein bands in SDS PAGE reduction electrophoresis Albuminutes immuno nanospheres were rounded with clear green fluorescence by immunofluorescence test Under microscope, we observed that BIU 87 cells were covered with the As 2O 3 (HAS NS) BDI 1 and that As 2O 3 (HAS NS) BDI 1 moved with the BIU 87 cells The albuminutes immuno nanospheres were tightly junctioned with the BIU 87 cells Specific killing activity of As 2O 3 (HAS NS) BDI 1 on bladder tumor cells was observed by acridine orange staining and 3H TdR incorporation assays Conclusions As 2O 3 (HAS NS) BDI 1 might bind specifically against BIU 87 cells, thus leading to high activity of killing bladder tumor cells
